Automatic door operator



April 9, 1963 J. M. LINDER AUTOMATIC DOOR OPERATOR I5 Sheets-Sheet 1Filed Feb. 15, 1960 mm T 0 mw V4 m F 2 x m w m 3 mm m m a 5 o 7 m 2 NZ Ia w b 5 3 m u fl A 'OKNEYS 3 Sheets-Sheet 2 Filed Feb. 15, 1960 f /5 k 5w 5 Q M 4 HM a 4 J 1 i W m g" y m a/ 4 Q ,7/ i: o ,a w KL M w g x k "l5L @fi Q 4 a a W "w 6 H a "m Av 27 mh w I 7 a F 6L .50 m w M INVEN TOR.Jose; M. 4 l1v0 M24, Madam ATTORNEY;

ass-4,927 AWUMATIQ D0912 @PERATQR Josef M. Liuder, Delavan, Wia,assignor to frown Industries, EEC. Delavan, Wis, a corporation ofWiscousin Filed Feb. 15, 196i), Ser. No. 8,640 2 Qlaims. (Cl. 268-34) Myinvention relates to improvements in an automatic door operator.

More particularly stated this invention relates to that type ofautomatic door operator used to operate a swinging door under control oftreadle switches of conventional characteristics but the actual dooroperating mechanism is liquid-controlled and involves novel featuresproviding simplified liquid actuation; rapid acceleration anddeceleration of door operation without destructive jerking of the door;a simplified single duct liquid system between power apparatus and theactual small door operating unit; liquid braking system in combinationwith spring bias to door closed position; and a novel combination ofliquid and compressed air pressure maintenance whereby liquid pressureto the actual door operator is maintained for ready application of doormoving forces.

It will be noted that the actual direct door operator is completelyself-contained except for a single duct liquid pressure conduit andtherefore there are no solenoids, limit switches or other electricalequipment immediately associated with the door operator.

In the drawings:

FIG. 1 is a perspective view, somewhat diagrammatically setting forthentrance and exit doors equipped with this invention.

FIG. 1A is a plan view fragmentarily showing a door and door frame withthe door operator of this invention, the degree of door opening beingshown in dotted lines.

FIG. 2 is a diagrammatic view showing the pressure liquid and electricalsystems embodying the invention.

FIG. 3 is an elevation showing the door operator, the door frame and thetop fragmentary portion of a door equipped in accord with thisinvention.

'FIG. 4 is a section on line 44 of FIG. 3.

FIG. 5 is an enlarged sectional view on line 55 of FIG. 4.

FIG. 6 is a section on line 6-6 of FIG. 5.

FIG. 7 is a vertical section through the reservoir and main pressureliquid control valve; the electromagnetic operators of the valves beingshown in elevation.

FIG. 8 is a section on line 8-8 of FIG. 7.

FIG. 9 is a vertical section through the liquid pressure maintainingunit.

FIG. 10 is a section on line 10-10 of FIG. 7.

As shown in FIG. 1 a typical environment in which this invention may beused includes a door 10 or a pair of doors Ill-11 which are mounted toswing upon hinges such as those shown at 12 for door 10 it beingunderstood that door 10 is mounted in frame 13 for swinging motiontoward the viewer and door 11 is mounted in its frame 14 for swingingmotion away from the viewer. In a suitable position, in this case at thetop of the door frame 13 the actual door operator 15 is mounted to thedoor frame in such position that a door operating arm 16 forming a partof the door operator 15 and extending therefrom is attached at itsoutward swinging end to a lost-motion bracket 17. A similar dooroperator 15' shown in dotted lines in FIG. 1 is mounted on the otherside of the door frame 14 in position to swing door 11 to open positionand permit it to close.

There are available on the market various means com prising treadles1'8, 19, 20, and 21, each equipped with a pressure operated switchresponsive to the pressure exerted upon the treadle when a personapproaches a door or when gagement with housing 47.

Patented Apr. 9, 1963 such a person steps on a treadle after goingthrough the door opening. Assuming that door 10 and its associatedtreadles 18-19 are concerned in a particular installation, it will beseen upon examination of FIG. 2 that treadle 18, when provided with theweight of an approaching person, will close a switch 25 in a circuitincluding the secondary in a transformer 26 and door opening wire 27 forenergization of coil 28. Some form of time delaying mechanism showndiagrammatically at 29 gives assurance that door opening switch 30 willnot open immediately when the weight of the person is removed fromtreadle 18. Also when the weight of the person leaves treadle 13 andbears on treadle 19 holding switch 31 which is a pressure switch beneathtreadle 19 will be closed so as to delay still further the opening ofswitch 30 until the person has cleared the zone in which the doorswings. When the weight of the person is removed from treadle 19 door 10may close.

This being the environment in which my invention is to be incorporatedit will be understood that when the switch 30 is closed, my dooroperator now to be described will be activated and when the dooroperator has been described my new control means therefore will be morereadily understood.

Reference has already been made to the fact that the door operator 15 or15' is equipped with a door operating arm 16. As shown in FIGS. 3 to 5this arm 16 is fixed upon a sturdy oscillatable shaft 35 extendingupwardly through the box-like casing 36 of operator 15. This casingcomprises an upper and a lower substantial frame plate 37, 38respectively, spaced apart by frame posts 39 at the corners of thecasing. It is between the frame plates 37 and 38 that the principlestructural elements of the door operator, other than arm 16 are housed,and there is a cover plate 40 to complete the enclosure on three sidesthereof exposed to public view when the operator is installed againstthe frame 13 or 14 as shown in the drawings.

The at rest position of arm 16 is its position when door It) is closedand the arm 16 with its shaft 35 is biased to this position by a heavyhelical spring 45, the inner end of which as shown in FIG; 4 in dottedlines is hooked into engagement with shaft 35 at 46. The outer end ofthe spring 45 is hooked to a cylindrical spring housing 47 as shown at48 so that the spring may be placed under tension by revolving thecylindrical spring housing 47 and then engaging pawl 49 in one of manynotches 50 as shown most clearly in FIGS. 3 and 4. It will be understoodthat pawl 49 is pivotally mounted upon a screw 51 in threaded engagementwith frame plate 38 and a spring 52 constantly urges the pawl 49 into enIt will be understood that this is a relatively permanent adjustment forthe life of a particular spring.

The mechanism thus far described assures that operator 15 installed asshown in FIG. 1 will move the hinged door 10 to closed position withsuch degree of closing force as is adjustably determined by the bias ofspring 45 eX- erted for oscillation of shaft 35 and arm 16.

Also fixed upon shaft 35 is a piston operated arm 55 so disposed withrespect to shaft 35 and arm 16 that when door ltlis closed the arm 55 isin the position shown in FIG. 4. This means that the outer end of thearm 55 being provided with a pivotal connection at '56 to piston rod 57will have disposed the piston rod in its extremeinner position relativeto cylinder 58. It willbe understood that cylinder 58 and piston 59comprise a double acting liquid responsive door actuator for liquidpressurewhich may be termed a braking function as will now be described.

Referring now to the diagram in FIG. 2, it will be seen that the doubleacting cylinder and piston arrangement is provided with a liquidpressure supply duct 60 and a connection 61 for liquid is connected tothe other end of the cylinder. Each of the tubes 66 and 61 is providedwith a check valve 62 to prevent passage of liquid from the cylinder,but tube 60 has a by-pass 63 and tube 61 has a by-pass 64; and each ofthe by-passes has a cam operated needle valve, 65 for by-pass 63 and 66for 'by-pass 64, so arranged that thepre'ssure of liquid leaving thecylinder 58 is relieved by the particular needle valve and a cam betweenthe ends of the two needle valves may adjustably close a valve or permitthe valve to open.

The two check valves and their respective by-passes are each providedwith a separate valve cage shown in FIG. 4 at 70 and '71 and it will beunderstood that the cam 67 is mounted upon shaft 72 to which as shown inFIG. 4 a cam arm 73 is fixed. This cam arm is connected to pistonoperator arm 55 by means of damping pitman 74 and the angular relationof the piston operated arm 55, the damping pitman 74-, cam arm 73, andcam 67 is such that as piston 59 approaches the inner end of thecylinder 53 as shown in FIG. 2 to force liquid out of the left end ofthe cylinder through duct 60, needle valve 65 is held closely to but notactually upon its seat so as to slow up the motion of the piston. Alsoit will be understood that as the piston 59 approaches its outer limitof motion (toward the right as seen in FIG. 2) the relationship of theparts is such that cam 67 will then be holding needle valve 66 close tobut not against its seat so as to slow up the motion of the piston inthat direction.

While the diagrammatic disclosure in FIG. 2 explains the generalfunctional arrangement of parts relating to these by-pas'ses and thecontrol thereof, FIG. shows an englarged detail of the bypass ductthrough cages 7i and 71 and shows a mounting block 75 shaped to carrybearing member 76 for shaft 72 and to provide guideway for a camfollower 77 and the cam of valve 65; also for cam follower 78 mounted onthe cam end of valve 66, and there are compression springs 79 and 30respectively for these needle valves tending to urge the valves andtheir followers to cam contacting position. Suitable lock nuts 82 areprovided to secure whatever threaded adjustment there may be providedbetween the respective valves and their followers.

Because cylinder 58 is mounted to a post at 90 which is in pivotalrelation to frame plates 37 and 38 the valve cages 70 and 71 andmounting block 75 are secured in unitary assembly with a plate 912 andeach of the valve cages 70 and '71 being provided with a very heavytubular connection at 93 and 94 respectively with cylinder 58 theswinging motion of this assembly in accord with the arcuate path of theconnection at 56 is accommodated. Also inspection of FIG. 3 will showthe manner in which a surge tank 95 is secured to this assembly underthe cylinder so that surge conduit 96 connected at the bottom of thesurge tank 95 may pass to that tank and receive from it liquid whichwill fill the cylinder 58 to the right of the piston 59 as seen in FIG.2.

Having thus described the relatively conventional treadle apparatus andelectrical connections adjacent the doors and 11, and having describedthe door operating mechanism of this invention, attention is nowdirected to the control means and apparatus for power operation of thepiston and cylinder 59-58.

The secondary of the transformer 26 referred to above is also used as alow voltage source for a circuit 100 controlled by a float switch 101whereby a motor 102 may be energized by the line as indicated in FIG. 2.This motor is mechanically connected directly through coupling 103 witha positive displacement pump 104 which is only energized when reservoir105 has a' sufficient supply of reserve liquid 1&6 to cause float switch101 to 61 be closed. At such times the pump withdraws liquid from thereservoir through supply tube 197 and forces it through pressure tube108 into liquid pressure tank zone 109. 1 refer to this portion of tank111 as a liquid pressure zone because that portion of tank 111 lyingabove a flexible and elastic diaphragm 110 comprises an air pressurezone provided initially and constantly with air 'at adequate pressure sothat the liquid at 109' is available under pressure for functionaloperation of the cylinder and piston at Sit-59. A suitable air valve 112is provided for supply of air by means of an air pump or other airconnection and this air under pressure remains in the zone above thediaphragm as a quickly responsive means for forcing liquid through pipe113 into cylinder 58 whenever the door is to be opened. That portion ofpipe 113 shown in dotted lines iii FIG. 3 is flexible to accommodatemovement of the cylinder.

A master valve 115 in pipe 113 determines when the liquid pressure is tobe applied to the piston for door opening operation. The electricalcontrol of this master valve will now be described.

When the door opening switch 3%) closes, it energizes cell 122, thearmature 123 of which is pulled upwardly (See FIGS. 2 and 7) so as tomechanically overcome the pressure upon master valve 115 theretoforeimpressed upon that valve by valve stem 124 and its compression spring125. The pressure of spring 125 is adequate to hold the master valve 115to its seat against the pressure in the chamber 111 above diaphragm 110.Immediately upon the release of the mastervalve 115 the liquid from thesupply at 1119 under pressure is supplied to the cylinder 58 and a dooropening operation results, since the pressure maintained in chamber 109is adequate to overcome the spring 45 which has theretofore held thedoor in closed position.

The door, having been opened in the manner described, will stay open solong as the treadle 18 or the treadle 19 sustains sufficient weight toclose the switch 25 or 31, but when the weight is relieved from thetreadle, switch 30 will open, coil 122 will be de-ener'gized and themaster valve will be forced to return to closed position under pressureof spring 125. Whereupon liquid pressure at the left of piston 59 asseen in FIG. 2. will be relieved through by-pass 63 at a rate governedby the position of cam 67 and the liquid will be returned through returnduct 126. p

FIG. 7 shows not only the master valve 115 but also shows a completemaster valve arrangement for control of another door thus providingmeans for control of a companion door operator, as for instance, door 11under control of treadles 20 and 21.

Resume From the above description it will be seen that pump 104 and itsmotor 102 under control of float switch 101 will-pump liquid fromreservoir into liquid pressure tank 109 against the diaphragm which isunder pressure of air in tank 111. Therefore, it is the pressureprovided initially and thereafter according to the pressure of airsupplied through valve 112 that determines the forces with which piston59 is caused to overcome the spring 45 and open the particular door towhich the piston and its red are connected.

When master valve is opened, the movement of the valve to close thereturn duct 126 is immediate so that the liquid from pressure tank 109cannot pass into reservoir 105. But when the door has been opened andits related treadles have been relieved of pressure, thede-energiz'ation of coil 122 permits the immediate closure of the mastervalve and spring 45 is permitted to return the piston to the left asseen in FIG. 2 under control of needle valve 65 in turn controlled bycam 67. This cam is oscillated in accord with the movement of pitman 74.Therefore, the final portion of the door movement to closed position isslowed. The needle valve approaching its seat permits only :a relativelyslow bleeding of the liquid firom cylinder 58 around the bypass 63 andinto reservoir 105. Of course, in accord with this invention, the dooropening movement under pressure of the liquid moving into the cylinderis rapid until cam 67 moves to push the needle valve 66 to a positionrelative to a bypass 64. Then the liquid to the right of the piston 59as seen in FIG. 2 may slowly pass into surge tank 95 as will be clear inthe above description. Surge tank 95 has a certain amount of air in theupper portion thereof to act as a very low pressure cushion and tank 95therefore need not be vented.

The capacity of reservoir 105 and of pressure tank 109 is ample tosupply a number of door operators and each door operator as shown inFIGS. 3, 4, and 5 need only be provided with a single high pressure line113 with a master valve 115.

I claim:

1. A door operator and operating system therefore to open a framed doorbiased to closed position in said frame and equipped with a treadleoperated control switch, an hydraulic operated cylinder and pistonassembly mechanically connected to the frame and to the door andincluding an arm attached to the door for swinging motion responsive tothe position of the piston in the cylinder, an electric circuitincluding a source of current and said treadle switch with a coil of amagnetically responsive master valve; said valve having a cagecomprising a portion of an hydraulic system including said cylinder, aliquid filled reservoir, a motorized pump, an air cushioned pressuretank and hydraulic connections between these elements whereby the pumpfills the pressure tank and supplies liquid under pressure through saidmaster valve to the cylinder; an electric circuit for said motorincluding a float operated switch in said reservoir energized by closureof said switch, the cage of said master valve being provided with aby-pass connected to the reservoir whereby to return liquid from thecylinder to the reservoir when the master valve is closed to preventpassage of liquid from the pressure tank to the cylinder, said mastervalve being biased to closed position by means adequate to overcome thepressure of liquid from the pressure tank.

2. The operator and system of claim 1 in which the cylinder and pistoncomprise a double acting assembly in which one end of the cylinder isconnected to the master valve and the other end of the cylinder isprovided with a hydraulic surge tank connection, and adjustable needlevalves respectively positioned to control liquid flow from either end ofthe cylinder, said needle valves being connected for adjustable responseto the position of the arm.

References Cited in the file of this patent UNITED STATES PATENTS2,276,338 Potter et a1. a Mar. 17, 1942 2,893,725 Katz July 7, 19592,911,210 Ferguson Nov. 3, 1959 FOREIGN PATENTS 1,094,963 France Dec.15, 1954

1. A DOOR OPERATOR AND OPERATING SYSTEM THEREFORE TO OPEN A FRAMED DOORBIASED TO CLOSED POSITION IN SAID FRAME AND EQUIPPED WITH A TREADLEOPERATED CONTROL SWITCH, AN HYDRAULIC OPERATED CYLINDER AND PISTONASSEMBLY MECHANICALLY CONNECTED TO THE FRAME AND TO THE DOOR ANDINCLUDING AN ARM ATTACHED TO THE DOOR FOR SWINGING MOTION RESPONSIVE TOTHE POSITION OF THE PISTON IN THE CYLINDER, AN ELECTRIC CIRCUITINCLUDING A SOURCE OF CURRENT AND SAID TREADLE SWITCH WITH A COIL OF AMAGNETICALLY RESPONSIVE MASTER VALVE; SAID VALVE HAVING A CAGECOMPRISING A PORTION OF AN HYDRAULIC SYSTEM INCLUDING SAID CYLINDER, ALIQUID FILLED RESERVOIR, A MOTORIZED PUMP, AN AIR CUSHIONED PRESSURETANK AND HYDRAULIC CONNECTIONS BE-